For ONTRApages Premium and ONTRApages in ONTRAPORT accounts you can use a wildcard subdomain A record (he will know what this is!) It is not available for ONTRApages Free.
It will allow you to create new subdomains for your ONTRApages on the fly from within ONTRAPORT. Your main website at "www.your-domain.com" will remain in effect with the content it has. From within ONTRAPORT you will be able to specify a subdomain to replace that "www" portion of the URL like this: "offers.your-domain.com" or "members.your-domain.com" You can add additional landing pages to that same domain by using a page name in the URL: "offers.your-domain.com/spring2015" and "offers.your-domain.com/fall2015" will both work.
This means you cannot have any other subdomains on the same domain, however. Your webmaster should know how this will impact you.
- Create the wildcard subdomain A record following your domain registrar's instructions or in your control panel for the domain. We have some general instructions here: http://support.ontraport.com/entries/...
- Point the wildcard A Record to 22.214.171.124
- Allow the DNS record to propagate; this can take up to 48 hours, although it is usually much faster than that (within 2 hours in most cases).
- Create a test ONTRApages page and host it at "test.your-domain.com". Make sure you save it, then test by entering that URL into your browser.
Note: Changing your DNS records is very risky, and if you don't know what you are doing you can lose all of your website's existing content and email. This should only be done by someone who is experienced. You assume the full risk for doing this.